Solenoid valve

ABSTRACT

An annular magnetic plate has planar parallel side surfaces, one of them contacting an end surface of a solenoid coil carrier and the other contacting an opposite surface of a solenoid terminal carrier. The plate has outer and inner edges, in contact respectively with an inside surface of a magnetic shell and an outside surface of a tubular magnetic element, to complete the magnetic circuit induced by the solenoid coil and to mechanically interconnect the solenoid coil and terminal carriers. The coil, shell, plate and tubular element coaxially surround a magnetic core member and a valve member operated thereby, to magnetically move these members in the tubular element.

Hans et al.

SOLENOID VALVE Inventors: Waldemar Hans; Helmul Staih, both of Bamherg;Alfred Grub, ()berstenfeld. all of (lei-many Assignee: Robert Bosch(i.n1 b.l'l.. Stuttgart.

Germany Filed: June 5 1974 Appl. No; 476,706

Foreign Application Priority Data Jul 15. I973 German t v i i i v t r r133784 US. Cl. 4 i i i 335/255; 335/25U; 335/278 lnl. (fl. i i 4 r i rHUIF 7/08 Field Of Search 335/278 2(i() 251. 255

References Cited UNITED STATES PATENTS Furrextei' et al.

llll 3,909,758

X Sept. 30, 1975 Anastasia et ul. 335/260 Flentge 335/278 I 5 7 IABSTRACT An annular magnetic piute has planar parallel side sur faces.one of them contacting an end surface of a solenoid cuil carrier and theother contacting an opposite surface of a solenoid terminal carrier. Theplate has outer and inner etlges in contact respectively with an insidesurface of a magnetic shell and an outside surtaee of a tubular magneticelement. to complete the magnetic circuit induced by the solenoid coiland to mechanically interconnect the solenoid coil and terminalcarriers. The coil shell, plate and tubular element cuaxially surround amagnetic core member and a valve member operated thereby. to magnetieallmove these members in the tubular element,

12 Claims. 2 Druvting Figures U.S. Patent Sept. 30,1975

SOLENOID VALVE BACKGROUND OF THE INVENTION The invention relates to asolenoid valve of the type wherein a solenoid coil surrounds afluid-tight tubular element, said element surrounding a magnetic coreand a valve member connected to said core; the solenoid being surroundedby a magnetic shell and a magnetic plate being provided for completing amagnetic circuit between the shell and a magnetic end portion of thetubular element.

Solenoid valves of this type have heretofore met with difficulties. In atypical earlier construction of this type, the inner tubular element wasthreaded to a valve housing and was provided with a bolt secured to thetubular element; the coil and magnetic plate were clamped to the bolt,while the shell was fastened to the bolt by an additional nut. Theconstruction was complex and expensive and did not allow desirablecoaxial arrangement of a coil terminal carrier, at the end of the shell.

Difficulties have also been encountered in other prior constructions ofthe indicated type including, for example, a rapid acting miniaturesolenoid valve wherein the coil was arranged between two collars on theinner tubular element and was surrounded by a cover injectionmoldedthereon; the magnet was fastened to the valve housing by a coupling notwith the aid ofa tubular magnetic shell. The construction again wasrather expensive; it also had the defect that a burnt out coil could bereplaced only together with the inner tubular element.

SUMMARY OF THE INVENTION It is an object of the invention to avoiddifficulties of the aforementioned types.

It is another object to provide a solenoid valve of simple constructionand wherein the several elements are readily individually removable andreplaceable.

Another important object is to minimize losses of electromagnetic energyin such a solenoid valve.

It is also desired that the construction be easily adaptable to variousvalves and applications thereof. Still other objects may be noted fromthe detailed disclosure which follows.

The objects have been acheived by combining the solenoid coil of asolenoid valve with a solenoid terminal carrier axially spacedtherefrom, and with a magnetic end plate, inserted to fill the spacebetween the solenoid and the terminal carrier.

By virtue of this construction the solenoid unit is particularly easy toassemble and repair. A coil unit (coil, terminal carrier and magneticend plate) can simply be inserted by sliding it onto the inner tubularpart of the magnet. Prior to such insertion of the coil unit, the

magnetic end plate is removably inserted between the coil carrier andits terminal carrier, by radially moving this plate into the spacebetween these carriers. The two carriers are advantageouslyinterconnected by a rigid bar or bridge; the magnetic end plate can havea relatively small peripheral recess fitting this bar or bridge andwhich does not significantly unbalance the symmetry of the magneticcircuit. The several parts are mechanically interconnected withoutbolting or the like. by this insertion of the end plate on the solenoidcarriers and are held in proper arrangement by the ensuing insertion ofthe solenoid carriers and plate on the tubular inner part. The entiremagnet and solenoid unit can then be secured to the valve housing bythreads on the magnetic shell. The coil terminals can be advantageouslyaxially fed into one end of the unit. The parts which constitute themagnetic circuit are closely fitted to each other so that losses ofenergy are minimized.

For this latter purpose the magnetic shell may have a first end portion,adjacent the valve, in contact with a flange element extending outwardlyfrom the inner tubular element. The opposite end of the magnetic shelldesirably has a collar, an inner surface of which is in contact with anadjacent end surface of the coil terminal carrier. In this way the shellnot only serves as a part of the magnetic circuit but also firmly holdsthe coil carrier and terminal carrier on the inner tubular element,while holding the entire magnetic unit on the valve housing.

Other features and advantages of the invention may be noted from thedetailed description which follows.

The novel features which are considered as charac teristic for theinvention are set forth in particular in the appended claims. Theinvention itself, however, both as to its construction and its method ofoperation, together with additional objects and advantages thereof, willbe best understood from the following description of specificembodiments when read in connection with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a sectional view of asolenoid valve according to the invention, the view being taken alonglines Il in FIG. 2; and

FIG. 2 is another sectional view, taken along lines 2-2 in FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A magnet unit generallydesignated by numeral 10 is threadedly connected to an end portion 11 ofthe valve I2, this valve being shown only in part as variousconstructions of it are known to the art and are not part of thisinvention.

The magnet unit It) is shown as having a fluid-tight inner tubularportion 13, one end of which is surrounded by a flange element 14. Theinner tubular portion 13 has a non-magnetic tube element 15, betweenmagnetic tube elements, one of which constitutes a cap 16 at the end ofthis unit opposite flange element l4. This cap 16, as well as the otherend portion of the tubular part I3 and flange element 14, consists ofmagnetic material (this term being used herein to indicate magneticallypermeable material). As further shown a yoke I7 is inserted in the innertubular element 13 adjacent the flange I4, with apertures 18 extendingthrough the yoke to connect a fluid chamber of the valve 12 with a corechamber 19 in the inner tubular part 13. In this chamber 19 a magneticcore 22, biassed toward valve 12 by a compression spring 21, isslidingly movable over a short distance, this core having apertures I8for balancing fluid pressures on both sides of the core. A valve pin 23,slidingly guided in yoke 17, can be moved by core 22 either by threadingthe pin into the core or by simple contact between the pin and core. asis well known in the construction of valves. As is similarly understood,a spacer ring or shim 24 is interposed between the valve end of theinner tubular element I3 and a sleeve 26, forming part of the valveportion 11, a flat contact surface 25 being provided between theseelements 24, 26.

According to the invention, a solenoid coil unit 27, surrounding theinner tubular element 13 and comprising a coil carrier 28 with a coil 29thereon is axially spaced from a solenoid terminal carrier 31, coaxialwith the coil carrier and firmly or if preferred rigidly connectedtherewith by a bar or bridge 32, and mag netic end plate 35substantially fills the space between these carriers Outer peripheralportions of coil carrier 28, terminal carrier 31 and plate 35 havesubstantially identical diameters.

The bar or bridge 32 is disposed at or adjacent the peripheries of thecarriers 28, 31. As best shown in FIG. 2, this bar or bridge 32 extendsonly over a limited arcuate distance.

in further accordance with the invention, an inner aperture 33 extendsthrough the coil carrier 28 and plate 35 and into the terminal carrier31. The diameter of this aperture substantially coincides with the outerdiameter of the inner magnetic element 13 to establish firm and accuratecontact therewith. Transversely of this aperture 33, the coil unit 27has a recess 34 which separates the coil carrier 28 from the terminalcarrier 31, an end surface 34a being formed on the coil carrier 28 andbeing contacted by a side surface of the magnetic end plate 35 whichfills the recess 34 and also contacts a surface of the terminal carrier31, opposite the end surface 34a. The end plate 35 has a smallperipheral recess 32, fitting around the sides of the bar or bridge 36;the plate 35 having a large arcuate edge portion contacting the insideof a magnetic shell 46, to be described presently, and having a completecircular edge in contact with the magnetic inner cap 16.

The end portions of coil 29 extend across the recess 34, for example onthe two sides of a reinforcing rib 37 on the bar 32, from the coilcarrier 28 to terminal carrier 31, where they are suitably fastened tocontact vanes 39, 41. These vanes as shown, extend in directionsparallel to the axis of the unit, away from valve 12. Injection moldedmaterial 42 is shown as surrounding coil 29 and contact carrier 31 andas providing a receptacle 43 for a connector socket (not shown). Theinjection molded covering 42 also has a shoulder 44, advantageouslyprovided with three lugs 45 extending axially away from the valve.

A magnetic shell 46 surrounds the solenoid unit 27. This shell has avalve end 47 abutting against a surface of the flange element 14, whilethe shell also has an inwardly projecting collar 48 remote from thevalve 12 and in contact with lugs 45, axially projecting from theterminal carrier 3]. Threads 49 are formed on the outer surface of theshell 46 to fit into inner threads on the valve portion 1 1. Forthreading the shell 46 into the valve portion 11, flat faces 51 areformed on the shell adjacent the terminal carrier 31.

The assembly of the solenoid magnet unit is very simple. Initially thesolenoid unit 27 (28, 31, 32) is held apart from the inner magnetictubular part [3. The magnetic plate 35 is then inserted in thetransverse recess 34 of this unit 27 to establish coaxial positions ofthe parts 27, 35. Incident to this insertion the recess 36 of plate 35is engaged with the bar or bridge 32 of solenoid unit 27. The resultingsubcombination 27, 35 can then be simply slid onto the inner tubularelement 13. Next, the shell 46 is applied coaxially to these parts andis threaded onto valve portion 11, thereby at the same time fasteningthe subcombination 27, 35 to the inner tubular element 13 and fasteningthe entire magnet 10 to the valve portion 11. Surface engagement betweenthe collar 48 and the lugs 45 establishes proper equalization oflongitudinal tolerances of the solenoid unit 27, on inner magnetictubular means 13, when the shell 46 has been threaded into valve element11 to establish proper contact at the valve end 47 of the shell.

The several elements can be removed and interchanged easily. Theconstruction allows continued use of unimpaired parts, whilefacilitating replacement of damaged parts. In particular the solenoidunit 27 can be removed and replaced, without loss of the magnetic plate35, inner tubular element 13, or shell 46. At the same time the parts46, 35, l6, l4 and 13 constituting the stationary unit of the magneticcircuit, can always be kept in intimate contact with one another;similarly the solenoid portions 28, 31 can always be firmlyinterconnected by plate 35; and thus it is possible to fully avoidmagnetic losses due to vibrations and the like.

The new magnet also facilitates application to large numbers ofdifferent valve constructions, particulary by virtue of the fact thatthe elements are so easily removable from one another and replaceable byother elements.

It is believed that the operation of the new solenoid valve will beobvious, to persons skilled in the art, from the structural descriptiongiven herein.

It will be understood that each of the elements described above, or twoor more together, may also find a useful application in other types ofsolenoid valve differing from the types described above.

While the invention has been illustrated and described as embodied in asolenoid valve, it is not intended to be limited to the details shown,since various modifications and structural changes may be made withoutdeparting in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist ofthe present invention that others can, by applying current knowledge,readily adapt it for various applications without omitting featuresthat, from the standpoint of prior art, fairly constitute essentialcharacteristics of the generic or specific aspects of this invention.

What is claimed as new and desired to be protected by Letters Patent isset forth in the appended claims:

1. A solenoid valve comprising tubular magnetic means having a magneticcore member and a valve member both provided within said tubularmagnetic means, said valve member being connected with said magneticcore member; a magnetic shell spaced radially outwardly from androtatable with respect to said tubular magnetic means, said magneticshell having an open end portion; solenoid coil means surrounding saidtubular means; solenoid terminal means spaced axially from said coilmeans and having terminals connected to said coil means which areaccessible through said open end portion of said shell; and a magneticplate insorted in said shell and around said tubular means forcompleting a magnetic circuit induced by said coil means so as tomagnetically move said magnetic core member and said valve member, saidplate substantially filling the space between said coil means and saidterminal means whereby said rotatable magnetic shell is readilymountable and removable with respect to said tubular magnetic means forfacilitating the continued use of unimpaired parts and the replacementof damaged parts.

2. The solenoid valve defined in claim 1 wherein the sides of said plateand adjacent surfaces of said coil and terminal means are planar andparallel to facilitate disassembly of said plate from said coil andterminal means and reassembly thereof, on removal thereof from saidtubular means.

3. The solenoid valve defined in claim 2 wherein said shell isconstructed to releasably hold said solenoid coil means, terminal meansand plate on said tubular means.

4. The solenoid valve defined in claim 1 including contact vanes on saidsolenoid terminal means. extending away from said valve member parallelto the axis of the shell.

5. The solenoid valve defined in claim 1 including a flange elementclosely surrounding the tubular magnetic means, said shell having an endportion abutting against said flange element.

6. The solenoid valve defined in claim 5 including outer threads on saidshell for connecting said shell to a portion of the valve.

7. The solenoid valve defined in claim 1 including a collar projectinginwardly from an end portion of said shell remote from said valvemember, said terminal means having lug means axially extending oppositesaid collar and engaged by the same.

8. The solenoid valve defined in claim 1, including a cover of syntheticplastic material surrounding said coil means.

9. The solenoid valve defined in claim 1, including an end portion ofsaid shell remote from said valve memher, and flat faces on said endportion for turning said shell to fasten it to a part of the valve.

10. A solenoid valve comprising a magnetic shell; tubular magnetic meansradially inwardly spaced from said shell; a magnet core and a valvemember connected thereto, both in said tubular means; solenoid coilmeans in said shell surrounding said tubular means; solenoid terminalmeans having terminals connected to said coil means and accessiblethrough an end of said shell, said terminal means having a bar-likebridge member firmly joining said terminal means to said coil means andmaintaining the latter axially spaced from said terminal means; and amagnetic plate inserted in said shell and around said tubular means forcompleting a magnetic circuit induced by said coil means, said platesubstantially filling the space between said coil means and saidterminal means.

11. The solenoid valve defined in claim 10 wherein said plate is annularexcept for a recess therein. corresponding to said bridge, and has acircular inner surface for full peripheral contact with said tubularmeans.

12. The solenoid valve defined in claim 11 wherein said annular platehas an extended, arcuate outer surface in contact with an inside surfaceof said shell.

1. A solenoid valve comprising tubular magnetic means having a magneticcore member and a valve member both provided within said tubularmagnetic means, said valve member being connected with said magneticcore member; a magnetic shell spaced radially outwardly from androtatable with respect to said tubular magnetic means, said magneticshell having an open end portion; solenoid coil means surrounding saidtubular means; solenoid terminal means spaced axially from said coilmeans and having terminals connected to said coil means which areaccessible through said open end portion of said shell; and a magneticplate inserted in said shell and around said tubular means forcompleting a magnetic circuit induced by said coil means so as tomagnetically move said magnetic core member and said valve member, saidplate substantially filling the space between said coil means and saidterminal means, whereby said rotatable magnetic shell is readilymountable and removable with respect to said tubular magnetic means forfacilitating the continued use of unimpaired parts and the replacementof damaged parts.
 2. The solenoid valve defined in claim 1 wherein thesides of said plate and adjacent surfaces of said coil and terminalmeans are planar and parallel to facilitate disassembly of said platefrom said coil and terminal means and reassembly thereof, on removalthereof from said tubular means.
 3. The solenoid valve defined in claim2 wherein said shell is constructed to releasably hold said solenoidcoil means, terminal means and plate on said tubular means.
 4. Thesolenoid valve defined in claim 1 including contact vanes on saidsolenoid terminal means, extending away from said valve member parallelto the axis of the shell.
 5. The solenoid valve defined in claim 1including a flange element closely surrounding the tubular magneticmeans, said shell having an end portion abutting against said flangeelement.
 6. The solenoid valve defined in claim 5 including outerthreads on said shell for connecting said shell to a portion of thevalve.
 7. The solenoid valve defined in claim 1 including a collarprojecting inwardly from an end portion of said shell remote from saidvalve member, said terminal means having lug means axially exTendingopposite said collar and engaged by the same.
 8. The solenoid valvedefined in claim 1, including a cover of synthetic plastic materialsurrounding said coil means.
 9. The solenoid valve defined in claim 1,including an end portion of said shell remote from said valve member,and flat faces on said end portion for turning said shell to fasten itto a part of the valve.
 10. A solenoid valve comprising a magneticshell; tubular magnetic means radially inwardly spaced from said shell;a magnet core and a valve member connected thereto, both in said tubularmeans; solenoid coil means in said shell surrounding said tubular means;solenoid terminal means having terminals connected to said coil meansand accessible through an end of said shell, said terminal means havinga bar-like bridge member firmly joining said terminal means to said coilmeans and maintaining the latter axially spaced from said terminalmeans; and a magnetic plate inserted in said shell and around saidtubular means for completing a magnetic circuit induced by said coilmeans, said plate substantially filling the space between said coilmeans and said terminal means.
 11. The solenoid valve defined in claim10 wherein said plate is annular except for a recess therein,corresponding to said bridge, and has a circular inner surface for fullperipheral contact with said tubular means.
 12. The solenoid valvedefined in claim 11 wherein said annular plate has an extended, arcuateouter surface in contact with an inside surface of said shell.